1. Field of the Invention
The present invention relates to a linear image sensor for receiving a reflected light from an original that is irradiated with light and converting the reflected light into an electric signal, which is applied to an image reader such as a FAX machine, a scanner, or a copying machine.
2. Description of the Related Art
FIG. 5 is a circuit diagram showing a conventional image sensor. The conventional image sensor is formed of plural photoelectric conversion elements 101 and plural read switching elements 102 each of which are connected in parallel, a scanning circuit 103 that controls the read switching elements 102, a switching element 107 that outputs signals from the read switching elements 102, a control circuit 106 that controls the switching element 107, a scanning input signal producing circuit 104, and a scanning output signal producing-circuit 105 (refer to JP 01-298863 A (page 3, FIG. 1)).
The scanning circuit 103 is formed of a shift register which is formed of n data flip flop circuits, and an input terminal of the scanning circuit 103 is inputted with a scanning pulse through the scanning input signal producing circuit 104 that is connected in series. The scanning circuit 103 controls the read switching elements 102 so as to output an image signal to an image signal output terminal 108 in synchronism with a clock signal from a clock input terminal 109.
Plural image sensor ICs are linearly mounted on a substrate to constitute a linear image sensor.